parameterized classes

# Define
class my_mysql (
  $param1 = 'default1',
  $param2 = 'default2'
) {
  $myhash = {
    'param1' => $param1,
    'param2' => $param2,
  }
}

# Declare
class { 'my_mysql':
  param2 => 'override_value',
}